Composite spinal facet implant with textured surfaces

ABSTRACT

Implementations described and claimed herein provide a distal leading portion of a composite spinal implant for implantation in a spinal facet joint. In one implementation, the distal leading portion includes a distal leading end, a proximal trailing end, a first face, and a second face. The distal leading end has a distal surface generally opposite a proximal surface of the proximal trailing end. The first face has a first surface that is generally parallel with a second surface of the second face. The first and second faces extend between the distal leading end and the proximal trailing end, such that the first and second surfaces slope upwardly from the distal lead end to the proximal trailing end along a length of extending proximally. The first and second surfaces having one or more textured features adapted to provide friction with the spinal facet joint.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119 to U.S.provisional patent application 61/705,375, which was filed Sep. 25, 2012and entitled “Composite Spinal Facet Implant,” and to U.S. provisionalpatent application 61/777,643, which was filed Mar. 12, 2013 andentitled “Composite Spinal Facet Implant with Textured Surfaces.”

The present application claims priority to and is a continuation-in-partof U.S. patent application Ser. No. 13/614,372 filed on Sep. 13, 2012,and entitled Vertebral Joint Implants And Delivery Tools. U.S. patentapplication Ser. No. 13/614,372 is a continuation of U.S. patentapplication Ser. No. 12/653,283, which was filed on Dec. 10, 2009, nowU.S. Pat. No. 8,425,558, and entitled “Verbal Joint Implants andDelivery Tools.” U.S. patent application Ser. No. 12/653,283 claimspriority to and is a continuation-in-part of U.S. patent applicationSer. No. 12/455,814, which was filed on Jun. 5, 2009, now U.S. Pat. No.8,361,152 and entitled “Facet Joint Implants and Delivery Tools.” U.S.patent application Ser. No. 12/455,814 claims priority to and is acontinuation-in-part of U.S. patent application Ser. No. 12/317,682,which was filed on Dec. 23, 2008, now U.S. Pat. No. 8,267,966, andentitled “Facet Joint Implants and Delivery Tools.”

U.S. patent application Ser. No. 12/455,814 further claims priorityunder 35 U.S.C. §119 to U.S. provisional patent application 61/169,601,which was filed on Apr. 15, 2009 and entitled “Facet Joint Implants andDelivery Tools.”

U.S. patent application Ser. No. 12/317,682 claims priority under 35U.S.C. §119 to U.S. provisional patent application 61/109,776, which wasfiled Oct. 30, 2008 and entitled “Facet Joint Implants,” and U.S.provisional patent application 61/059,723, which was filed on Jun. 6,2008 and entitled “Spine Distraction Device.”

Each of the aforementioned applications is hereby incorporated byreference in its entirety into the present application.

TECHNICAL FIELD

Aspects of the present disclosure relate to a device for distracting thespine and more particularly to a tool for distracting a facet joint ofthe spine and an implant for maintaining the distracted position of thejoint.

BACKGROUND

Chronic back problems cause pain and disability for a large segment ofthe population. Adverse spinal conditions may be characteristic of age.In particular, spinal stenosis (including, but not limited to, central,canal, and lateral stenosis) and facet arthropathy may increase withage. Spinal stenosis results in a reduction of foraminal area (i.e. theavailable space for the passage of nerves and blood vessels), which maycompress cervical nerve roots and cause radicular pain. Both neckextension and ipsilateral rotation, in contrast to neck flexion, mayfurther reduce the foraminal area and contribute to pain, nerve rootcompression, and neural injury.

Cervical disc herniations may be a factor in spinal stenosis and maypredominantly present upper extremity radicular symptoms. In this case,treatment may take the form of closed traction. A number of closedtraction devices are available that alleviate pain by pulling on thehead to increase foraminal height. Cervical disc herniations may also betreated with anterior and posterior surgery. Many of these surgeries areperformed through an anterior approach, which requires a spinal fusion.These surgeries may be expensive and beget additional surgeries due tochanging the biomechanics of the neck. There is a three percentincidence of re-operation after cervical spine surgery. Moreover, thesesurgeries may be highly invasive leading to long recovery times.

There is a need in the art for implants, delivery systems, and methodsof implantation that facilitate the fusion of a spinal facet joint via aminimally invasive or percutaneous procedure from, for example, aposterior approach.

It is with these observations in mind, among others, that variousaspects of the present disclosure were conceived and developed.

SUMMARY

Implementations described and claimed herein address the foregoingproblems, among others, by providing a distal leading portion of acomposite spinal implant for implantation in a spinal facet joint. Inone implementation, the distal leading portion includes a distal leadingend, a first face, and a first side. The distal leading end has a distalsurface generally opposite a proximal surface of a proximal trailingend. The first face has a first surface that is generally parallel witha second surface of a second face. The first and second faces extendbetween the distal leading end and the proximal trailing end, such thatthe first and second surfaces slope upwardly from the distal lead end tothe proximal trailing end along a length of extending proximally. Thefirst and second surfaces having one or more textured features adaptedto provide friction with the spinal facet joint. The first side has afirst side surface generally opposite a second side having a second sidesurface. The first side surface and the second side surface each have aslot extending distally from a notch formed in the proximal surfaceuntil reaching a sloped transition extending from an inner surface ofthe slot to the side surface of the first side or the second side.

Other implementations are also described and recited herein. Further,while multiple implementations are disclosed, still otherimplementations of the presently disclosed technology will becomeapparent to those skilled in the art from the following detaileddescription, which shows and describes illustrative implementations ofthe presently disclosed technology. As will be realized, the presentlydisclosed technology is capable of modifications in various aspects, allwithout departing from the spirit and scope of the presently disclosedtechnology. Accordingly, the drawings and detailed description are to beregarded as illustrative in nature and not limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-D are isometric, top plan, distal leading end, and side views,respectively, of an example distal leading portion of a composite spinalimplant.

FIG. 2A is an isometric view of another example of a distal leadingportion of a composite spinal implant.

FIG. 2B shows an isometric view of an example proximal trailing anchorportion of a composite spinal implant.

FIGS. 2C-2D illustrate side and top plan views, respectively, of acomposite spinal implant employing the distal leading portion of FIG. 2Aand the proximal trailing anchor portion of FIG. 2B.

FIGS. 3A-C depict isometric, top plan, and proximal trailing end views,respectively, of example composite implants employing different proximaltrailing anchor portions.

FIGS. 4A-D show isometric, top plan, distal leading end, and side views,respectively, of an example distal leading portion of a composite spinalimplant including textured faces having small pyramids.

FIGS. 5A-D illustrate isometric, top plan, distal leading end, and sideviews, respectively, of an example distal leading portion of a compositespinal implant including textured faces having large pyramids.

FIGS. 6A-D are isometric, top plan, distal leading end, and side views,respectively, of an example distal leading portion of a composite spinalimplant including textured faces having dimples.

FIGS. 7A-D show isometric, top plan, distal leading end, and side views,respectively, of an example distal leading portion of a composite spinalimplant including textured faces having grit.

FIGS. 8A-D depict isometric, top plan, distal leading end, and sideviews, respectively, of an example distal leading portion of a compositespinal implant including textured faces having pits.

FIG. 9 shows an example delivery device and guide tube configured tominimally invasively deliver a composite spinal implant.

FIG. 10 shows a perspective view the delivery device of FIG. 9 and adetailed view of a distal end of the delivery device.

FIG. 11 illustrates a perspective view of the guide tube of FIG. 9.

FIG. 12 depicts a perspective view of an example decorticator.

FIG. 13 shows a perspective view of an example injector.

FIG. 14 is a perspective view of an example chisel.

FIG. 15 illustrates an example place holding chisel.

FIG. 16 depicts a perspective view of an example malleting tool.

DETAILED DESCRIPTION

Aspects of the present disclosure generally involve devices and methodsfor treating spinal stenosis. Spinal stenosis reflects a narrowing ofone or more areas of the spine often in the upper or lower back. Thisnarrowing can put pressure on the spinal cord or on the nerves thatbranch out from the compressed areas. Individual vertebrae of the spineare positioned relative to each other and their separation is maintainedby discs separating main vertebral bodies and by capsules positionedwithin facet joints. The discs and capsules are separated from the boneof their respective joints by cartilage. Spinal stenosis is oftenindicative of degeneration of a disc, a capsule, or the cartilage in ajoint, which leads to a compression of the joints and the narrowingmentioned.

As such, in one aspect, a device for distracting a facet joint of thespine is provided to remedy this condition. The device may include atool and an implant for distracting and maintaining the distractedposition of the joint. The device may be adapted to access a facet jointby inserting a delivery tool and an implant, forcibly separate theassociated articular surfaces with the tool, the implant, or both, andleave the implant in place to maintain the separation of the articularsurfaces. This approach may allow for maintaining the distraction of thejoint, thereby relieving symptoms associated with spinal stenosis.

In one particular aspect, a composite spinal implant for implantation ina spinal facet joint to bring about the fusion of the spinal facet jointis provided. The composite spinal implant includes a distal leadingportion and a proximal trailing anchor portion. The distal leadingportion includes at least one face having a textured surface thatprovides friction between the spinal facet joint and the implant.

For a detailed description of an example distal leading portion 100 of acomposite spinal implant, reference is made to FIGS. 1A-D, which areisometric, top plan, distal leading end, and side views, respectively.

The distal leading portion 100 may be formed of a bone or bonesubstitute material. In one implementation, the distal leading portion100 includes a distal leading end 102 generally opposite a proximaltrailing end 104, a first face 106 generally opposite a second face 108,and a first side 110 generally opposite a second side 112. In oneimplementation, the first and second sides 110 and 112 each have alength 160 of approximately 10 mm, and the distal leading end 102 andthe proximal trailing end 104 each have a length 156 of approximately 5mm.

The first face 106 extends between the distal leading end 102 and theproximal trailing end 104. In one implementation, the first face 106 isgenerally parallel with the second face 108. For example, the first face106 may extend from the distal leading end 102 to the proximal trailingend 104 at an angle of approximately 0° to 15° relative to the secondface 108. As such, a height of the proximal trailing end 104 may begreater than or equal to a height of the distal leading end 102. In oneimplementation, the first and second faces 106 and 108 include texturedfeatures 114 that provide friction between the spinal facet joint andthe implant.

In the implementation shown in FIGS. 1A-D, the distal leading end 102includes a distal surface 116 and the proximal trailing end 104 includesa proximal surface 118. In one implementation, the distal and proximalsurfaces 116 and 118 are planar surfaces forming a generally rectangularshape. In one implementation, the distal surface 116 has a height 152that is approximately 0.84 mm, and the proximal surface 118 has a height154 that is approximately 2.25 mm. The distal surface 116 includes afirst pair of distal edges 128 extending between the first and secondsides 110 and 112 and a second pair of distal edges 134 extendingbetween the first and second faces 106 and 108. Similarly, the proximalsurface 118 includes a first pair of proximal edges 128 and a secondpair of proximal edges 120 extending between the first and second faces106 and 108. In one implementation, where the height of the proximaltrailing end 104 is greater than the height of the distal leading end102, the height of the second pair of proximal edges 120 is greater thanthe height of the second pair of distal edges 134, such that a surface124 of the first face 106 and a surface 130 of the second face 108 slopeupwardly from the distal leading end 102 to the proximal trailing end104 along a length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and thesurface 130 of the second face 108 are planar surfaces having agenerally rectangular shape formed from the length 140 and a width 126that is generally coextensive with the first pair of edges 128. Thefirst and second sides 110 and 112 each include a side surface 132extending between the distal leading end 102 and the proximal trailingend 104. In one implementation, the side surface 132 is a generallyplanar surface having a pair of opposed edges that are generallycoextensive with the second pair of distal edges 134 and the second pairof proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of thesecond face 108 include the textured features 114. In the implementationshown in FIGS. 1A-D, the textured features 114 are one or more ridgesextending generally perpendicularly from the surfaces 124 and/or 130along the length 140. Each of the ridges includes an inner surface 142generally opposite an outer surface 144. In one implementation, theouter surface 144 of each of the ridges is generally planar andcoextensive with the side surface 132, and the inner surface 142 of eachof the ridges is a generally planar surface that is generallyperpendicular to the surface 124 of the first face 106 and/or thesurface 130 of the second face 108. In one implementation, each of theridges has a saw toothed profile defined by a plurality of teeth havinga leading distal face 148, a trailing proximal face 150, and a tip 146formed at an intersection between the faces 148 and 150. The trailingproximal face 150 has a slope that is different from a slope of theleading distal face 148. For example, the trailing proximal face 150 hasa slope that is greater than the slope of the leading distal face 148.

Further, the height of the tips 146 may increase along the length 140,such that teeth positioned near the proximal trailing end 104 have agreater height than teeth positioned near the distal leading end 102.For example, a height 158 extending between the tip 146 of a toothpositioned on the first face 106 and the tip 146 of a tooth positionedon the second face 108 at the distal leading end 102 may beapproximately 2.69 mm, and a height 162 extending between the tip 146 ofa tooth positioned on the first face 106 and the tip 146 of a toothpositioned on the second face 108 at the distal leading end 102 may beapproximately 3.68 mm. The tip 146 may be a truncated flat surface, apoint, or other shapes. Further, it will be appreciated that the firstand second faces 106 and 108 may include any number or configuration ofridges or teeth and that the textured features 114 may cover all or aportion of the surface 124 of the first face 106 and/or the surface 130of the second face 108.

In one implementation, the first and second sides 110 and 112 eachinclude a slot 136 defined in the side surface 132 extending distallyfrom a notch 122 formed in the proximal surface 118 at an approximatecenter of each of the second pair of proximal edges 120. As such, theslot 136 is generally centered in the side surface 132 between thesurface 124 of the first face 106 and the surface 130 of the second face108. In one implementation, the slot 136 is generally dimensionallyconstant for a majority of a length of the slot 136 extending from thenotch 122 until reaching a sloped transition 138 extending from an innersurface of the slot 136 to the side surface 132.

As can be understood from FIG. 2A, in one implementation, the distalleading portion 100 includes at least one of a first groove 164 or asecond groove 166 defined in the proximal surface 118 and extending intothe surfaces 124 or 130, respectively. The first and second grooves 164and 166 are adapted to engage a proximal trailing anchor portion 200.

In one implementation, as shown in FIG. 2B, the proximal trailing anchorportion 200 includes a body 202 and one or more anchors 204. The anchor204 is supported by the body 202 and configured to extend at least oneof outwardly from the body 202 or outwardly and distally from the body202. The proximal trailing anchor portion 200 may be formed of abiocompatible metal, ceramic, polymer, or any combination thereof. Insome implementations, the composite spinal implant may be entirelyformed of bone or bone substitute material. In this case, the proximaltrailing anchor portion 200 may be excluded from the composite spinalimplant and the overall length of the distal leading portion 100extended.

The body 202 includes a distal leading end 206 generally opposite aproximal trailing end 208, a first face 210 generally opposite a secondface 212, and a first side 214 generally opposite a second side 216. Inone implementation, the first and second faces 210 and 212 includetextured features 218. For example, the textured features 218 mayinclude one or more ridges similar to the ridges of the distal leadingportion 100 described with respect to FIGS. 1A-D. Other implementationsof the proximal trailing anchor portion 200 may include any number orconfiguration of the textured features 218 covering all or a portion ofthe faces 210 and 212.

As can be understood from FIGS. 2A-2D, the first and second grooves 164and 166 in the distal leading portion 100 align with correspondingopenings (e.g., an opening 224) in the body 202 of the proximal trailinganchor portion 200 through which the anchor 204 extends so as to allowthe anchor 204 to extend through at least a portion of the proximaltrailing anchor portion 200 and at least a portion of the distal leadingportion 100.

As such, when the proximal trailing anchor portion 200 and the distalleading portion 100 are implanted in the facet joint to form a compositespinal implant, the distal leading end 206 of the body 202 of theproximal trailing anchor portion 200 abuts in a generally planar surfacecontact with the proximal trailing end 104 of the distal leading portion100. With the portions 100 and 200 so abutted, slots 220 in the sides214 and 216 of the body 202 of the proximal trailing anchor portion 200are generally aligned and dimensionally consistent with the respectiveslots 136 in the distal leading portion 100, such that a notch 222 inthe distal leading end 206 of the proximal trailing anchor portion 200is aligned with each of the notches 122 of the distal leading portion100. In one implementation, the slots 220 extend the full length of thebody 202 between opposing notches 222 centered along a height of thesides 214 and 216 of the proximal trailing anchor portion 200. Further,when so abutted, each of the side surfaces 132 of the distal leadingportion 100 is generally coextensive with a surface of the sides 214 or216 of the body 202 of the proximal trailing anchor portion 200, and thetextured features 114 of the distal leading portion 100 are generallyaligned and similarly spaced with respect to the textured features 218of the proximal trailing anchor portion 200.

As can be understood from FIGS. 3A-C, different proximal trailing anchorportions 200 with a variety of anchors 204 and openings 224 may beutilized. For example, a composite spinal implant 300 includes a pair ofgenerally parallel circular openings 224 extending through the body 202of the proximal trailing anchor portion 200. A composite spinal implant302 includes a pair of offset circular openings 224 extending throughthe body 202 of the proximal trailing anchor portion 200 through whichan anchor 204 in the form of a relatively small curved member extends. Acomposite spinal implant 304 includes a relatively large opening 224extending through the body 202 of the proximal trailing anchor portion200 through which an anchor 204 in the form of a screw extends. Acomposite spinal implant 306 includes a pair of offset circular openings224 extending through the body 202 of the proximal trailing anchorportion 200 through which an anchor 204 in the form of a relativelylarge curved member extends. It will be appreciated that the anchor 204may be one or more of nails, barbed members, threaded members, curvedmembers, screws, and the like. A proximal trailing end of the anchor 204is actionable at the proximal trailing end 208 of the body 202 so as tocause the anchor 204 to extend from the body 202.

For additional examples of the distal leading portion 100 with varioustextured features 114, reference is made to FIGS. 4A-8D. It will beappreciated that the proximal trailing anchor portion 200 may besimilarly modified to include a variety of textured features 218.

Referring to FIGS. 4A-D, in one implementation, the distal leadingportion 100 includes the distal leading end 102 generally opposite theproximal trailing end 104, the first face 106 generally opposite thesecond face 108, and the first side 110 generally opposite the secondside 112. In one implementation, the first and second sides 110 and 112each have a length 406 of approximately 10 mm, and the distal leadingend 102 and the proximal trailing end 104 each have a length 402 ofapproximately 5 mm.

The first face 106 extends between the distal leading end 102 and theproximal trailing end 104. In one implementation, the first face 106 isgenerally parallel with the second face 108. A height of the proximaltrailing end 104 may be greater than or equal to a height of the distalleading end 102. In one implementation, the first and second faces 106and 108 include textured features 114 that provide friction between thespinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distalsurface 116 and the proximal trailing end 104 includes the proximalsurface 118. In one implementation, the distal and proximal surfaces 116and 118 are planar surfaces forming a generally rectangular shape. Inone implementation, the distal surface 116 has a height 404 that isapproximately 2.8 mm. The distal surface 116 includes a first pair ofdistal edges 128 extending between the first and second sides 110 and112 and a second pair of distal edges 134 extending between the firstand second faces 106 and 108. Similarly, the proximal surface 118includes a first pair of proximal edges 128 and a second pair ofproximal edges 120 extending between the first and second faces 106 and108. In one implementation, where the height of the proximal trailingend 104 is greater than the height of the distal leading end 102, theheight of the second pair of proximal edges 120 is greater than theheight of the second pair of distal edges 134, such that a surface 124of the first face 106 and a surface 130 of the second face 108 slopeupwardly from the distal leading end 102 to the proximal trailing end104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and thesurface 130 of the second face 108 are planar surfaces having agenerally rectangular shape formed from the length 140 and the width 126that is generally coextensive with the first pair of edges 128. Thefirst and second sides 110 and 112 each include the side surface 132extending between the distal leading end 102 and the proximal trailingend 104. In one implementation, the side surface 132 is a generallyplanar surface having a pair of opposed edges that are generallycoextensive with the second pair of distal edges 134 and the second pairof proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of thesecond face 108 include the textured features 114. In oneimplementation, the textured features 114 are a plurality of protrusions400 extending generally perpendicularly from the surfaces 124 and/or 130along the length 140. In the implementation shown in FIGS. 4A-D, theprotrusions 400 have a pyramidal shape, including four generallytriangular faces and a rectangular base that is generally parallel tothe respective surfaces 124 and/or 130. The rectangular base formsgenerally right angles that are coextensive with angles formed by thewidth 126 and the length 140 of the respective surfaces 124 and/or 130.Each face of the protrusions 400 is adjacent to two other faces of thesame protrusion 400 that extend outwardly from the respective surfaces124 and/or 130 where they adjoin to form a tip. The protrusions 400shown in FIGS. 4A-D are relatively small pyramids having, for example, aheight to the tip ranging from approximately 0.25 mm and 0.5 mm and baseedges having a length between approximately 0.5 mm and 1.0 mm.

In one implementation, the protrusions 400 are arranged in rows, suchthat the rectangular base of each of the protrusions 400 abut the basesof adjacent protrusions 400. A plurality of the protrusions 400 extendfrom the first side 110 to the second side 112 to form the rows, and therows, in turn, extend from the distal leading end 102 to the proximaltrailing end 104 to form a series of rows. Further, it will beappreciated that the first and second faces 106 and 108 may include anynumber or configuration of the protrusions 400 and that the texturedfeatures 114 may cover all or a portion of the surface 124 of the firstface 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 eachinclude the slot 136 defined in the side surface 132 extending distallyfrom the notch 122 formed in the proximal surface 118 at an approximatecenter of each of the second pair of proximal edges 120. As such, theslot 136 is generally centered in the side surface 132 between thesurface 124 of the first face 106 and the surface 130 of the second face108. In one implementation, the slot 136 is generally dimensionallyconstant for a majority of a length of the slot 136 extending from thenotch 122 until reaching the sloped transition 138 extending from aninner surface of the slot 136 to the side surface 132.

Turning to FIGS. 5A-D, in one implementation, the distal leading portion100 includes the distal leading end 102 generally opposite the proximaltrailing end 104, the first face 106 generally opposite the second face108, and the first side 110 generally opposite the second side 112. Inone implementation, the first and second sides 110 and 112 each have alength 506 of approximately 10 mm, and the distal leading end 102 andthe proximal trailing end 104 each have a length 502 of approximately 5mm.

The first face 106 extends between the distal leading end 102 and theproximal trailing end 104. In one implementation, the first face 106 isgenerally parallel with the second face 108. A height of the proximaltrailing end 104 may be greater than or equal to a height of the distalleading end 102. In one implementation, the first and second faces 106and 108 include textured features 114 that provide friction between thespinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distalsurface 116 and the proximal trailing end 104 includes the proximalsurface 118. In one implementation, the distal and proximal surfaces 116and 118 are planar surfaces forming a generally rectangular shape. Inone implementation, the distal surface 116 has a height 504 that isapproximately 2.8 mm. The distal surface 116 includes a first pair ofdistal edges 128 extending between the first and second sides 110 and112 and a second pair of distal edges 134 extending between the firstand second faces 106 and 108. Similarly, the proximal surface 118includes a first pair of proximal edges 128 and a second pair ofproximal edges 120 extending between the first and second faces 106 and108. In one implementation, where the height of the proximal trailingend 104 is greater than the height of the distal leading end 102, theheight of the second pair of proximal edges 120 is greater than theheight of the second pair of distal edges 134, such that a surface 124of the first face 106 and a surface 130 of the second face 108 slopeupwardly from the distal leading end 102 to the proximal trailing end104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and thesurface 130 of the second face 108 are planar surfaces having agenerally rectangular shape formed from the length 140 and the width 126that is generally coextensive with the first pair of edges 128. Thefirst and second sides 110 and 112 each include the side surface 132extending between the distal leading end 102 and the proximal trailingend 104. In one implementation, the side surface 132 is a generallyplanar surface having a pair of opposed edges that are generallycoextensive with the second pair of distal edges 134 and the second pairof proximal edges 120.

The surface 124 of the first face 106 and/or the surface 130 of thesecond face 108 include the textured features 114. In oneimplementation, the textured features 114 are a plurality of protrusions500 extending generally perpendicularly from the surfaces 124 and/or 130along the length 140. In the implementation shown in FIGS. 5A-D, theprotrusions 500 have a pyramidal shape, including four generallytriangular faces and a rectangular base that is generally parallel tothe respective surfaces 124 and/or 130. The rectangular base formsgenerally right angles that are coextensive with angles formed by thewidth 126 and the length 140 of the respective surfaces 124 and/or 130.Each face of the protrusions 500 is adjacent to two other faces of thesame protrusion 500 that extend outwardly from the respective surfaces124 and/or 130 where they adjoin to form a tip. The protrusions 500shown in FIGS. 5A-D are relatively large pyramids having, for example, aheight to the tip ranging from approximately 0.5 mm and 1.5 mm and baseedges having a length between approximately 1.0 mm and 2.0 mm.

In one implementation, the protrusions 500 are arranged in rows, suchthat the rectangular base of each of the protrusions 500 abut the basesof adjacent protrusions 500. A plurality of the protrusions 500 extendfrom the first side 110 to the second side 112 to form the rows, and therows, in turn, extend from the distal leading end 102 to the proximaltrailing end 104 to form a series of rows. In one implementation, theremay be gaps between the rows that extend from the first side 110 to thesecond side 112 to accommodate relatively larger sized protrusions 500.Further, it will be appreciated that the first and second faces 106 and108 may include any number or configuration of the protrusions 500 andthat the textured features 114 may cover all or a portion of the surface124 of the first face 106 and/or the surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 eachinclude the slot 136 defined in the side surface 132 extending distallyfrom the notch 122 formed in the proximal surface 118 at an approximatecenter of each of the second pair of proximal edges 120. As such, theslot 136 is generally centered in the side surface 132 between thesurface 124 of the first face 106 and the surface 130 of the second face108. In one implementation, the slot 136 is generally dimensionallyconstant for a majority of a length of the slot 136 extending from thenotch 122 until reaching the sloped transition 138 extending from aninner surface of the slot 136 to the side surface 132.

As can be understood from FIGS. 6A-D, in one implementation, the distalleading portion 100 includes the distal leading end 102 generallyopposite the proximal trailing end 104, the first face 106 generallyopposite the second face 108, and the first side 110 generally oppositethe second side 112. In one implementation, the first and second sides110 and 112 each have a length 612 of approximately 10 mm, and thedistal leading end 102 and the proximal trailing end 104 each have alength 608 of approximately 5 mm.

The first face 106 extends between the distal leading end 102 and theproximal trailing end 104. In one implementation, the first face 106 isgenerally parallel with the second face 108. A height of the proximaltrailing end 104 may be greater than or equal to a height of the distalleading end 102. In one implementation, the first and second faces 106and 108 include textured features 114 that provide friction between thespinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distalsurface 116 and the proximal trailing end 104 includes the proximalsurface 118. In one implementation, the distal and proximal surfaces 116and 118 are planar surfaces forming a generally rectangular shape. Inone implementation, the distal surface 116 has a height 610 that isapproximately 5.6 mm. In one implementation, where the height of theproximal trailing end 104 is greater than the height of the distalleading end 102, the surface 124 of the first face 106 and the surface130 of the second face 108 slope upwardly from the distal leading end102 to the proximal trailing end 104.

In one implementation, the surface 124 of the first face 106 and thesurface 130 of the second face 108 are planar surfaces having agenerally rectangular shape, and the first and second sides 110 and 112each include the side surface 132 extending between the distal leadingend 102 and the proximal trailing end 104.

The surface 124 of the first face 106 and/or the surface 130 of thesecond face 108 include the textured features 114 defined therein. Inone implementation, the textured features 114 are a plurality of dimples600 having a generally spherical imprint or indentation 602 having aradial depth generally perpendicularly into the respective surfaces 124and/or 130. In one implementation, the dimples 600 are arranged in rows,such that the indentations 602 overlap with at least a portion of anadjacent indentation 602. A plurality of the dimples 600 extend from thefirst side 110 to the second side 112 to form the rows, and the rows, inturn, extend from the distal leading end 102 to the proximal trailingend 104 to form a series of rows. The effect creates a grid-like patternof the dimples 600 forming towers 604 between the indentations 602. Inone implementation, the towers 604 are generally planar surfaces. Thedegree of overlap of the indentations 602 and the depth of theindentations 602 can vary accordingly so as to provide an appropriateamount of friction and grip between the implant and the bone surface.For example, in one implementation, the indentations 602 may have avertical depth of approximately 0.25 mm to 1.0 mm and a diameter ofapproximately 0.5 mm to 1.5 mm. Further, it will be appreciated that thefirst and second faces 106 and 108 may include any number orconfiguration of the dimples 600 and that the textured features 114 maycover all or a portion of the surface 124 of the first face 106 and/orthe surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 eachinclude the slot 136 defined in the side surface 132 extending distallyfrom the notch 122 formed in the proximal surface 118 at an approximatecenter of each of the second pair of proximal edges 120. As such, theslot 136 is generally centered in the side surface 132 between thesurface 124 of the first face 106 and the surface 130 of the second face108. In one implementation, the slot 136 is generally dimensionallyconstant for a majority of a length of the slot 136 extending from thenotch 122 until reaching the sloped transition 138 extending from aninner surface of the slot 136 to the side surface 132.

Referring to FIGS. 7A-D, in one implementation, the distal leadingportion 100 includes the distal leading end 102 generally opposite theproximal trailing end 104, the first face 106 generally opposite thesecond face 108, and the first side 110 generally opposite the secondside 112. In one implementation, the first and second sides 110 and 112each have a length 706 of approximately 10 mm, and the distal leadingend 102 and the proximal trailing end 104 each have a length 702 ofapproximately 5 mm.

The first face 106 extends between the distal leading end 102 and theproximal trailing end 104. In one implementation, the first face 106 isgenerally parallel with the second face 108. A height of the proximaltrailing end 104 may be greater than or equal to a height of the distalleading end 102. In one implementation, the first and second faces 106and 108 include textured features 114 that provide friction between thespinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distalsurface 116 and the proximal trailing end 104 includes the proximalsurface 118. In one implementation, the distal and proximal surfaces 116and 118 are planar surfaces forming a generally rectangular shape. Inone implementation, the distal surface 116 has a height 704 that isapproximately 3.6 mm. The distal surface 116 includes a first pair ofdistal edges 128 extending between the first and second sides 110 and112 and a second pair of distal edges 134 extending between the firstand second faces 106 and 108. Similarly, the proximal surface 118includes a first pair of proximal edges 128 and a second pair ofproximal edges 120 extending between the first and second faces 106 and108. In one implementation, where the height of the proximal trailingend 104 is greater than the height of the distal leading end 102, theheight of the second pair of proximal edges 120 is greater than theheight of the second pair of distal edges 134, such that a surface 124of the first face 106 and a surface 130 of the second face 108 slopeupwardly from the distal leading end 102 to the proximal trailing end104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and thesurface 130 of the second face 108 are planar surfaces having agenerally rectangular shape formed from the length 140 and a width thatis generally coextensive with the first pair of edges 128. The first andsecond sides 110 and 112 each include the side surface 132 extendingbetween the distal leading end 102 and the proximal trailing end 104. Inone implementation, the side surface 132 is a generally planar surfacehaving a pair of opposed edges that are generally coextensive with thesecond pair of distal edges 134 and the second pair of proximal edges120.

The surface 124 of the first face 106 and/or the surface 130 of thesecond face 108 include the textured features 114. Further, the sidesurfaces 124, the distal surface 116, and/or the proximal surface 118may include the textured features 114. In one implementation, thetextured features 114 are a plurality of grit particles 700 extendinggenerally perpendicularly from the surfaces 124 and/or 130 along thelength 140. The grit particles 700 may be a variety of shapes adapted tofuse the implant to the bone surface. In the implementation shown inFIGS. 7A-D, the grit particles 700 have a semi-circular, bubble-likeshape. The grit particles 700 shown in FIGS. 7A-D have a diameterranging from approximately 0.1 mm and 1.0 mm.

In one implementation, the grit particles 700 are randomly adhered tothe respective surfaces 124 and 130, such that the surfaces 124 and 130may contain differences in the layout of the textured features 114. Thegrit particles 700 may be applied by a variety of suitable means toadhere the grit particles 700 to the material of the surfaces 124 and130. In another implementation, the grit particles 700 are arrangedrelatively uniformly (i.e., in rows or strips) on the respectivesurfaces 124 and 130. Further, it will be appreciated that the first andsecond faces 106 and 108 may include any number or configuration of thegrit particles 700 and that the textured features 114 may cover all or aportion of the surface 124 of the first face 106 and/or the surface 130of the second face 108.

In one implementation, the first and second sides 110 and 112 eachinclude the slot 136 defined in the side surface 132 extending distallyfrom the notch 122 formed in the proximal surface 118 at an approximatecenter of each of the second pair of proximal edges 120. As such, theslot 136 is generally centered in the side surface 132 between thesurface 124 of the first face 106 and the surface 130 of the second face108. In one implementation, the slot 136 is generally dimensionallyconstant for a majority of a length of the slot 136 extending from thenotch 122 until reaching the sloped transition 138 extending from aninner surface of the slot 136 to the side surface 132.

Turning to FIGS. 8A-D, in one implementation, the distal leading portion100 includes the distal leading end 102 generally opposite the proximaltrailing end 104, the first face 106 generally opposite the second face108, and the first side 110 generally opposite the second side 112. Inone implementation, the first and second sides 110 and 112 each have alength 806 of approximately 10 mm, and the distal leading end 102 andthe proximal trailing end 104 each have a length 802 of approximately 5mm.

The first face 106 extends between the distal leading end 102 and theproximal trailing end 104. In one implementation, the first face 106 isgenerally parallel with the second face 108. A height of the proximaltrailing end 104 may be greater than or equal to a height of the distalleading end 102. In one implementation, the first and second faces 106and 108 include textured features 114 that provide friction between thespinal facet joint and the implant.

In one implementation, the distal leading end 102 includes the distalsurface 116 and the proximal trailing end 104 includes the proximalsurface 118. In one implementation, the distal and proximal surfaces 116and 118 are planar surfaces forming a generally rectangular shape. Inone implementation, the distal surface 116 has a height 804 that isapproximately 3.9 mm. The distal surface 116 includes a first pair ofdistal edges 128 extending between the first and second sides 110 and112 and a second pair of distal edges 134 extending between the firstand second faces 106 and 108. Similarly, the proximal surface 118includes a first pair of proximal edges 128 and a second pair ofproximal edges 120 extending between the first and second faces 106 and108. In one implementation, where the height of the proximal trailingend 104 is greater than the height of the distal leading end 102, theheight of the second pair of proximal edges 120 is greater than theheight of the second pair of distal edges 134, such that a surface 124of the first face 106 and a surface 130 of the second face 108 slopeupwardly from the distal leading end 102 to the proximal trailing end104 along the length 140 extending proximally.

In one implementation, the surface 124 of the first face 106 and thesurface 130 of the second face 108 are planar surfaces having agenerally rectangular shape formed from the length 140 and a width thatis generally coextensive with the first pair of edges 128. The first andsecond sides 110 and 112 each include the side surface 132 extendingbetween the distal leading end 102 and the proximal trailing end 104. Inone implementation, the side surface 132 is a generally planar surfacehaving a pair of opposed edges that are generally coextensive with thesecond pair of distal edges 134 and the second pair of proximal edges120.

The surface 124 of the first face 106 and/or the surface 130 of thesecond face 108 include the textured features 114. Further, the sidesurfaces 124, the distal surface 116, and/or the proximal surface 118may include the textured features 114. In one implementation, thetextured features 114 are a plurality of pits 800 extending generallyperpendicularly into the surfaces 124 and/or 130 along the length 140.The pits 800 may be a variety of shapes adapted to fuse the implant tothe bone surface. For example, the pits 800 may be shaped like anegative imprint of the grit particles 700, the dimples 600, theprotrusions 400, 500 or any similar feature. In the implementation shownin FIGS. 8A-D, for example, the pits 800 are negative imprints of asemi-circular, bubble-like shape. The depth of such an imprint and theimprint diameter will vary accordingly to achieve adequate frictionbetween the implant and the bone. For example, the pits 800 shown inFIGS. 8A-D have a diameter ranging from approximately 0.1 mm and 1.0 mm.

The surfaces 124 and 130 may undergo a reductive surface treatment,including, without limitation, abrasive blasting, chemical treating, andthe like, to achieve the pits 800. In addition to a reductive surfacetreatment, an additive treatment may be used to texture the surfaces 124and 130 to add a pre-textured layer. In one implementation, the pits 800cover the respective surfaces 124 and 130 in a random orientation, suchthat the surfaces 124 and 130 may contain differences in the layout ofthe textured features 114. In another implementation, the pits 800 arearranged relatively uniformly (i.e., in rows or strips) on therespective surfaces 124 and 130. Further, it will be appreciated thatthe first and second faces 106 and 108 may include any number orconfiguration of the pits 800 and that the textured features 114 maycover all or a portion of the surface 124 of the first face 106 and/orthe surface 130 of the second face 108.

In one implementation, the first and second sides 110 and 112 eachinclude the slot 136 defined in the side surface 132 extending distallyfrom the notch 122 formed in the proximal surface 118 at an approximatecenter of each of the second pair of proximal edges 120. As such, theslot 136 is generally centered in the side surface 132 between thesurface 124 of the first face 106 and the surface 130 of the second face108. In one implementation, the slot 136 is generally dimensionallyconstant for a majority of a length of the slot 136 extending from thenotch 122 until reaching the sloped transition 138 extending from aninner surface of the slot 136 to the side surface 132.

As can be understood from FIGS. 9-16, a distraction system 900 isconfigured to minimally invasively or percutaneously deliverimplementations of the composite spinal implant including the distalleading portion 100 and optionally the proximal trailing anchor portion200 into a patient spinal facet joint space via, for example, aposterior approach. In one implementation, the system 900 includes adelivery tool 902 and a guide tube 904, both of which extend from arespective leading distal end 906, 907 to a respective trailing proximalend 908, 909. As can be understood from FIG. 9, the delivery tool 902can be receive in the lumen of the guide tube 904 to bring about thedelivery of the implant 100 into the target spinal facet joint. Thesystem 900 may further include a decorticator 936, an injector 948, achisel 960, a place holding chisel 974, and a malleting tool 980.

For a detailed description of the delivery tool 902, reference is madeto FIG. 10. In one implementation, the delivery tool 902 includes atubular body 910 with a handle arrangement 912 at the trailing proximalend 908. The handle arrangement 912 may further include one or moremembers 914 for engaging the guide tube 904 as can be understood fromFIG. 9. In one implementation, a plunger 916 extends through a lumen 918of the tubular body 910 and includes a handle 920 at the trailingproximal end 906. The plunger 916 may be used to distally push theimplant from an interference fit engagement with the arms 922 of thedelivery tool distal end 906.

In one implementation, the tubular body 910 at the leading distal end906 includes opposed prongs 922 between which the implant, including thedistal leading portion 100 and the proximal trailing anchor portion 200,may be supported. The prongs 922 include longitudinally extending ridgesthat are adapted to be received into and engage the respective slots 136and 220 of the distal leading portion 100 and the proximal trailinganchor portion 200. In one implementation, the plunger 916 is springbiased to keep the plunger 916 proximally displaced in the lumen 918 ofthe tubular body 910, such that distal force exerted against the handle920 causes the plunger 216 to distally displace to eject the implantfrom the tubular body 910 at the leading distal end 906.

Turning to FIG. 11, a detailed description of the guide tube or tool 904is provided. In one implementation, the guide tube 904 includes areceiving assembly 926 at a proximal end 909 and a pair of anchoringforks 934 at a distal end 907 with a generally tubular shaft 924extending there between. The anchoring forks 934 may be textured distalparallel prongs for accessing a spinal facet joint and through which thedelivery tool 902 can be routed to deliver the implant 100 in the facetjoint.

The guide tube 904 can also include a malleting anvil 930 having araised surface 932 positioned on the proximal face of the receivingassembly 926 adapted for contact with a distal end of a malleting head966 on the chisel 960 or on the delivery tool 902. Malleting on theproximal end of the chisel 960 or the delivery tool 902 can causelongitudinal forces along the length of the respective tool piece. Theselongitudinal forces can be transferred, at least partially, through thecontact between the malleting head and the malleting anvil 930.Accordingly, relative motion between the respective tool piece and theguide tube 904 can be prevented. As such, for example, at the distal end907 of the guide tube 904, the relative position of the distal end 972of the chisel 960 or the delivery tool 902 relative to the distal end907 of the guide tube 904 can be maintained. Further, in oneimplementation, the receiving assembly 926 includes a receiving portion928 for receiving and engaging the members 914 or 970 of the deliverytool 902 and the chisel 960, respectively, as can be understood fromFIG. 9.

As can be understood from FIG. 12, in one implementation, thedecorticator 936 includes a tubular shaft portion 938, an abrasivedistal end 944, and a handle 940 at a proximal end. The tubular shaft938 may have an inner radius substantially equal to an outer radius ofthe shaft 976 of the place holding or guide chisel 974 of FIG. 15 andmay allow for sliding movement of the decorticator 936 along the lengthof the chisel shaft 976 and rotationally around the chisel shaft 976. Insome implementations, the inner radius of the tubular shaft 938 may beslightly or substantially larger than the outer radius of the shaft 976of the chisel 974 allowing for more freedom of movement of thedecorticator 936.

The abrasive distal end 944 of the decorticator 936 may include serratedteeth 946 as shown, or may include a more flat annular surface with agritty surface. In the implementation shown in FIG. 12, the distal endof the tubular shaft portion 938 is chamfered and the serrated teeth 946are located on the distal most end of the chamfered end allowing for amore directed and controllable decorticating process. As such, thedecorticator 936 shown is well suited for the intra facet processreflected by many of the implementations described herein. That is, thehuman anatomy of the cervical spine may be such that the lateral mass ofthe facet joints are not perpendicular to the surface of the facetjoint.

Additionally, to properly place the prongs 934 of the place holdingguide chisel 974 within the joint, the guide chisel 974 may bepositioned substantially parallel to articular surfaces of the facetjoint. As such, the place holding or guide chisel 974 may not bepositioned perpendicular to the lateral masses of the facet joints andmay actually be directed with a downward slope as it extends in thedistal direction. Where the decorticator 936 has an non-chamferedannular end, depending on anatomy, the decorticator 936 may be able tobe placed in contact with the superior lateral mass, but may be unableto reach or contact the inferior lateral mass. In the presentimplementation, the chamfered end of the tubular shaft portion 938 willallow the distal tip of the chamfered end to reach and decorticate theinferior lateral mass. This chamfered distal end may define an angle tothe longitudinal axis. Additionally, the teeth 946 may be relativelylarge or they may relatively small and may extend along the fullperimeter surface of the chamfered end rather being positioned solely atthe tip of the chamfered end. Additionally, a beveled edge may run alongthe periphery of the chamfered end. That is, along the ovular shapecreated by the chamfered tubular shaft portion 938, the edge is beveled.As such, when the chisel 974 is inserted into the patient and/or whenthe decorticator 936 is advanced along the chisel 974, the beveled edgemay assist in avoiding tissue snags, and the decorticator 936 may beplaced in contact with the lateral mass of the facet joints in a muchsmoother process and may avoid damage to neighboring tissues.

The handle 940 of the decorticator 936 may include a gripping surfacealong its peripheral edge and may sleevably receive the tubular shaftportion 938. The handle 940 may also include radially extending bores942 adapted to receive a gripping tool to provide for better control anda higher amount of torsional leverage when decorticating the lateralmasses of the facet joint or to allow for malleting in the longitudinaldirection of the decorticator 936 to cause forceful decortication of thelateral mass. The decorticator 936 may then be retracted, rotated to anew radial position, advanced, and struck again for additionaldecortication.

Referring to FIG. 13, in one implementation, the injector 948 includes alongitudinal delivery shaft 950 and a seating feature 952. Thelongitudinal delivery shaft 950 may have any cross-section and may havea cross-sectional size adapted to fit within the guide tube 904. Thelongitudinal shaft 950 may have an opening 956 on its distal end 954 fordirecting bone paste out the distal end of the shaft 950 allowing thepaste to flow into and/or over the facet joint and/or outward toward thelateral mass of a facet joint. The seating feature 952 may include amember 958 positioned around the shaft 950, which may be sized andshaped to abut the receiving portion 928 of the guide tube 904. Theinjector 948 may be sleevably inserted into the guide tube 904 andadvanced such that the distal end of the shaft 950 is positioned betweenthe prongs 934.

As can be understood from FIG. 14, in one implementation, the chisel 960includes a generally cylindrical cross-section forming a shaft 962,which may have a radius substantially equal to the inner radius of thetubular shaft portion 924 of the guide tube 904 allowing for slidableinsertion of the chisel 960 within the guide tube 904. Alternatively,the radius of the shaft 963 may be smaller than the inner radius of thetubular shaft 924 providing for more play and adjustability of thechisel 960 and the guide tube 904 relative to one another. The chisel960 may include a single or doubly chamfered tip 972 at a distal end ormay have a coped distal end or a combination of coping and chamfering.The tip 972 may include a roughened surface on one or more sides to aidin anchoring or docking the chisel in the facet joint. Additionally,this roughened surface may allow for roughening or decorticating theinner surfaces of the facet joint. The tip 972 may have a length adaptedto extend substantially across the facet joint.

The chisel 960 may further include a handle assembly 964 may include amember 970 positioned around the shaft 962, which may be sized andshaped to abut the receiving portion 928 of the guide tube 904. Thechisel 1008 may also include a longitudinally extending lumen 968 and amalleting head 966.

Turning to FIG. 15, in one implementation, the placing holding or guidechisel 974 includes a shaft 976 and a distal tip 978, which may includea tip the same or similar to the chisel 960. For example, the chisel 974can include a coped and/or chamfered tip. Additionally, the chisel 974can include ridges. Additionally, the chisel 974 can include aradiopaque portion on the shaft 976 adapted to allow recognition of thelocation of the chisel 974 while avoiding occlusion of the lateral view.The radiopaque portion can include a straight, round, square, or othershaped piece of material positioned near the distal end of the chisel974 for locating the distal end. As also shown, the proximal end of thechisel 974 can include a hole extending transversely therethrough. Thehole can adapted to receive a transverse rod or shaft extending into thehole and/or through the hole. The rod or shaft and the chisel 974 canform a T-grip or L-shaped grip for use in pulling on the chisel 974 forremoval.

In one implementation, the place holding chisel 974 can be used as aplace holder without occluding the lateral view of a chisel and deliverytool positioned in a contralateral facet joint. That is, upon placementof the chisel 960 and the guide tool 904 in a first facet joint, thechisel 960 may be removed and replaced with the place holding chisel 974where the prongs 934 of the guide tube 904 maintain the position of thesystem 900. The guide tube 904 may also be removed and reassembled withthe chisel 960 once the place holding chisel 974 is properly positioned.The guide tube 904 and chisel 960 may then be inserted into thecontralateral facet joint or second joint. By replacing the chisel 960in the first joint with the place holding chisel 974, the location ofthe chisel 960 and guide tube 904 in the second joint may be morereadily ascertainable using lateral fluoroscopy. That is, if aradiopaque chisel or delivery device was left in place in the firstjoint, the fluoroscopic view of the contralateral facet joint would berelatively occluded. Upon placing the guide tube 904 properly in thesecond facet joint, the procedure above may continue. Upon completingtreatment of the second facet joint, the guide tube 904 may be sleevedover the place holding chisel 974 still positioned in and holding theplace in the first facet joint and the first facet joint may then betreated with the above procedure. It is noted that initial placement ofthe guide tube 904 can be conducted with the place holding chisel 974rather than the chisel 960 to avoid having to replace the chisel 960.

Referring to FIG. 16, in one implementation, the malleting tool 980 caninclude a longitudinally shaped shaft with a U-shaped decorticatorinterface 984 at one end and a chamfered tip 982 at the other end. Thedecorticator interface 984 can be adapted for positioning around theguide tube 904 in a position just proximal to a malleting element of thedecorticator 936. The u-shape of the decorticator interface 984 mayallow the malleting tool 980 to be placed in position from the side ofthe guide tube 904 and selectively used as required to forcibly advancethe decorticator 936.

The chamfered end of the tool 982 can be held in position while the usermallets near the decorticator interface end causing the interface 984 tocontact the malleting element on the decorticator 936. The decorticator936 may then be retracted, rotated to a new radial position, advanced,and struck again for additional decortication. The malleting tool 980may rotate with the decorticator 936 or it may remain in a positionconvenient for malleting. In addition to malleting, the malleting tool980 can be used to assist in separating several tools. That is, in somecases, the handles of a given tool piece can be difficult to separatefrom receiving portion. The chamfered tip 982 can be used to wedgebetween a given handle and the receiving portion to assist in separatingthe devices.

Other implementations of a distraction system 900 can be configured withalternative retaining and deployment (release or eject) methods, such asscrew drives, latches, snaps, cams, adhesives, magnets, or the like.

The delivery system components depicted in FIGS. 9-16 can be used tominimally invasively implant any of the implants 100 depicted in FIGS.1A-8D in a spinal facet joint that is the target of treatment. Forexample, in one embodiment, a percutaneous or minimally invasiveincision is made in the posterior region of the neck to lead to thetarget facet joint. The access chisel 974 depicted in FIG. 15 is routedthrough incision under fluoroscopic guidance until the tapered distaltip 978 resides in the target facet joint and the chisel shaft 976extends out of the patient via the incision. With the access chisel 974so positioned, the outer decorticator 936 of FIG. 12 can be grasped anddistally routed over the access chisel 974 such that the chisel shaft976 is received in the lumen that extends longitudinally through theouter decorticator 936. With the distal decorticating end 946 of theouter decorticator 936 abutting against one or more lateral massesadjacent the target facet joint, the outer decorticator 936 can berotated about the chisel shaft 976 to decorticate the bone surfaces ofthe lateral masses adjacent the target facet joint. Once decorticationof the lateral masses has been sufficiently achieved, the decorticator936 can be removed from about the chisel shaft 976 and from the patient.

With the place holding or access chisel 974 so positioned, the guidetool 904 of FIG. 11 is grasped and distally routed over the chisel 974such that the chisel shaft 976 is received in the guide tool lumen thatextends longitudinally through the guide tool shaft 924. The taperedforked distal end 907 of the guide tool 904 is distally advanced throughthe incision and along the chisel shaft 976 until the tapered forks 934of the guide tool 904 are positioned inside the target facet joint, thechisel tapered distal tip 978 being located between the pair of forks934 of the guide tool distal end 907, the guide tool shaft 924 extendingout of the patient via the incision.

With the guide tool 904 so positioned, the place holding or accesschisel 974 can be withdrawn out of the guide tool lumen and out of thepatient, leaving the guide tool tapered forked distal end 907 residingin the target facet joint and the guide tool shaft extending out of thepatient. The decorticating chisel 960 of FIG. 14 can then be distallyrouted through the lumen of the guide tool 904 to place the tapereddecorticating distal end 972 of the chisel 960 between the guide toolforks 934 located in the target facet joint space. The decorticatingchisel 960 can then be displaced distal-proximal to cause the tapereddecorticating distal end 972 of the chisel 960 to remove the cartilageof the target facet joint space located between the guide tool forks 934and further decorticate any associated bone surfaces of the target facetjoint space. Once the target facet joint space surfaces have beenprepped with the decorticating chisel 960, the chisel 960 can be removedfrom the lumen of the guide tool 904 and the patient.

The implant 100 is coupled to, and supported off of, the distal end 906of the implant delivery tool 902 of FIG. 10. As discussed above, thecoupling of the implant delivery tool distal end 906 with the implant100 may be achieved via interference fit engagement. With the implantsupported off of the distal end 906 of the implant delivery tool 902 ina manner similar to that depicted in FIG. 10, the implant 100, and thedelivery tool shaft 910 on which the implant 100 is supported, aredistally routed through the lumen of the guide tool 904 until theimplant 100 and the delivery tool distal end 906 are located in thetarget facet joint space between the pair of forks 934 of the guide tooldistal end 907, the delivery tool 902, the guide tool 904 and theimplant 100 being coupled together as depicted in FIG. 9. With theimplant 100 so positioned in the target spinal facet join space, theplunger 916 may be used to deposit the implant 100 into the targetspinal facet joint space by plunging the implant 100 from the deliverytool distal end 906 via corresponding manipulation of the plunger 916via its handle 920. Once the implant 100 is decoupled from the deliverytool 902 and deposited into the facet joint space, the delivery tool 902can be withdrawn from the guide tool 904, which is left in place withits forked distal end 907 occupying the facet joint space and theimplant 100 being located between the forks 934 of the guide tool 904.Where the implant 100 is the entirety of the implant and not simply adistal portion 100 of a composite implant 300 similar to that depictedwith respect to FIGS. 1A-3C, the use of the delivery tool 902 is nowcomplete with respect to this target spinal facet joint.

However, where the delivered implant 100 is actually a proximal portion100 of a composite spinal implant 300 similar to that depicted withrespect to FIGS. 2C-3C, the delivery of the distal anchoring portion 200of the composite spinal implant 300 may occur in one of two waysemploying the method of using the delivery tool 902 as just laid out inthe immediately preceding paragraph. For example, in one embodiment, thedelivery of the composite implant 300 may occur in a single deliveryusing the above-described methodology pertaining to the use of thedelivery tool 902, wherein the proximal portion 100 and the distalportion 200 are placed together to form the composite implant 300 andthen inserted into the spinal facet joint space via the delivery tool902 by the methodology just described.

Alternatively, in another embodiment, the distal portion 100 and theanchor portion 200 of the composite implant 300 are delivered inseparate trips of the delivery tool 902 down through the lumen of theguide tool 904. In other words, the distal implant portion 100 is firstcoupled to the delivery tool 902 and tracked down into the facet jointspace via the guide tool 904, and then the process is repeated bycoupling the proximal anchor portion 200 to the delivery tool 902 andtracking the proximal portion 200 down the guide tool 904 into the facetjoint space, abutting in the spinal facet joint space the distal face ofthe proximal portion 200 to the proximal face of the distal portion 100to establish the composite implant 300. Various tools can then beintroduced down the lumen of the guide tool 904 to act on the proximalend of the anchors 204 of the anchor portion 200 to cause the anchors204 to deploy from the anchor portion 200, thereby securing thecomposite implant 300 from backing out of the facet joint space.

With the implant 100 and forks 934 so positioned in the facet jointspace and the guide tool shaft 924 extending from the patient, bonegrowth promoting paste may be plunged down the lumen of the guide tool904 via the shaft 950 of the injector 948 being distally displaced downthe lumen to cause the bone paste to exit the distal end 907 of thedelivery tool 904 and extend about the implant 100 occupying the spinalfacet joint space. The injector 948 and guide tool 904 can then bewithdrawn from the patient, the implantation of the implant 100 in thefacet joint having been completed. The process can then be repeated foranother facet joint if needed.

For a further discussion regarding delivery systems and methodology, seeU.S. patent application Ser. No. 12/653,283, which was filed on Dec. 10,2009 and entitled “Verbal Joint Implants and Delivery Tools.”

The description above includes example systems, methods, techniques,instruction sequences, and/or computer program products that embodytechniques of the present disclosure. However, it is understood that thedescribed disclosure may be practiced without these specific details.

It is believed that the present disclosure and many of its attendantadvantages will be understood by the foregoing description, and it willbe apparent that various changes may be made in the form, constructionand arrangement of the components without departing from the disclosedsubject matter or without sacrificing all of its material advantages.The form described is merely explanatory, and it is the intention of thefollowing claims to encompass and include such changes.

While the present disclosure has been described with reference tovarious embodiments, it will be understood that these embodiments areillustrative and that the scope of the disclosure is not limited tothem. Many variations, modifications, additions, and improvements arepossible. More generally, embodiments in accordance with the presentdisclosure have been described in the context of particularimplementations. Functionality may be separated or combined in blocksdifferently in various embodiments of the disclosure or described withdifferent terminology. These and other variations, modifications,additions, and improvements may fall within the scope of the disclosureas defined in the claims that follow.

What is claimed is:
 1. A distal leading portion of a composite spinalimplant for implantation in a spinal facet joint, the distal leadingportion comprising: a distal leading end having a distal surfacegenerally opposite a proximal surface of a proximal trailing end; afirst face having a first surface that is generally parallel with asecond surface of a second face, the first and second faces extendingbetween the distal leading end and the proximal trailing end, such thatthe first and second surfaces slope upwardly from the distal lead end tothe proximal trailing end along a length extending proximally, the firstand second surfaces having one or more textured features adapted toprovide friction with the spinal facet joint; and a first side having afirst side surface generally opposite a second side having a second sidesurface, the first side surface and the second side surface each havinga slot extending distally from a notch formed in the proximal surfaceuntil reaching a sloped transition extending from an inner surface ofthe slot to the side surface of the first side or the second side. 2.The distal leading portion of claim 1, wherein the textured featuresinclude a ridge extending perpendicularly from each of the first andsecond surfaces along the length of the first and second surfaces, theridge including an inner surface generally opposite an outer surfacethat is coextensive with a respective side surface of the first andsecond sides, the ridge having a saw toothed profile defined by aplurality of teeth having a leading distal face, a trailing proximalface, and a tip formed at an intersection between the leading distalface and the trailing proximal face.
 3. The distal leading portion ofclaim 2, wherein the trailing proximal face has a slope that is greaterthan a slope of the leading distal face.
 4. The distal leading portionof claim 2, wherein a tip of one of the teeth positioned near the distalleading end has a height that is lower than a height of a tip of one ofthe teeth positioned near the proximal trailing end.
 5. The distalleading portion of claim 2, wherein each tooth of the plurality of teethhas a height that is greater than a height of its immediately proximaladjacent tooth.
 6. The distal leading portion of claim 1, wherein thetextured features include a plurality of protrusions extendingperpendicularly from each of the first and second surfaces.
 7. Thedistal leading portion of claim 6, wherein the protrusions each have apyramidal shape with a rectangular base that is generally parallel to arespective surface of the first face and the second face.
 8. The distalleading portion of claim 6, wherein the protrusions form relativelysmall pyramids.
 9. The distal leading portion of claim 6, wherein theprotrusions form relatively large pyramids.
 10. The distal leadingportion of claim 6, wherein the protrusions are arranged in rows, afirst row of the protrusions abutting a second row of the protrusions.11. The distal leading portion of claim 1, wherein the textured featuresinclude a plurality of dimples, each of the dimples having a generallyspherical indentation having a radial vertical depth generallyperpendicularly into a respective surface of the first face and thesecond face.
 12. The distal leading portion of claim 11, wherein thedimples are arranged in rows, each of the indentations overlapping withat least a portion of at least one adjacent indentation to form a tower.13. The distal leading portion of claim 1, wherein the textured featuresinclude a plurality of grit particles extending generallyperpendicularly from a respective surface of the first face and thesecond face.
 14. The distal leading portion of claim 13, wherein theplurality of grit particles are randomly adhered to the surfaces of thefirst face and the second face.
 15. The distal leading portion of claim1, wherein the textured features include a plurality of pits extendinggenerally perpendicularly into a respective surface of the first faceand the second face.
 16. The distal leading portion of claim 15, whereinthe plurality of pits cover a respective surface of the first face andthe second face in a random orientation.
 17. The distal leading portionof claim 15, wherein the plurality of pits are achieved as a result ofsurface treating the surfaces of the first face and the second face. 18.A composite spinal implant for implantation in a spinal facet joint, thecomposite spinal implant comprising: a distal leading portion having adistal leading end, a first face, and a first side, the distal leadingend having a distal surface generally opposite a proximal surface of aproximal trailing end, the first face having a first surface that isgenerally parallel with a second surface of a second face, the first andsecond faces extending between the distal leading end and the proximaltrailing end, such that the first and second surfaces slope upwardlyfrom the distal lead end to the proximal trailing end along a lengthextending proximally, the first and second surfaces having one or moretextured features adapted to provide friction with the spinal facetjoint, the first side having a first side surface generally opposite asecond side having a second side surface; and a proximal trailing anchorportion having a body and an anchor, the body having a distal leadingend generally opposite a proximal trailing end, a first face generallyopposite a second face, and a first side generally opposite a secondside, the anchor being supported in the body and configured to extend atleast one of outwardly from the body or outwardly and distally from thebody, the distal leading end of the body adapted to abut the proximaltrailing end of the distal leading portion to form the composite spinalimplant.
 19. The composite spinal implant of claim 18, wherein the firstside surface and the second side surface of the distal leading portioneach have a slot extending distally from a notch formed in the proximalsurface until reaching a sloped transition extending from an innersurface of the slot to the side surface of the first side or the secondside and the first side and the second side of the body of the proximaltrailing anchor portion each have a slot extending distally from a notchformed in a surface of the proximal trailing end of the body to a notchformed in a surface of the distal leading end of the body, the slots ofthe proximal trailing anchor portion being generally aligned anddimensionally consistent with the slots of the distal leading portionwhen the distal leading end of the body abuts the proximal trailing endof the distal leading portion.
 20. The composite spinal implant of claim18, wherein the distal leading portion includes a groove defined in theproximal surface and at least one of the surface of the first face orthe second face that aligns with an opening in the body of the proximaltrailing anchor portion through which the anchor extends into thegroove.